I have just experienced this same issue. I submit 4 tasks to 4 different
queues as a part of a single transaction. If multiple requests come in
rapid succession, the following exception is raised upon commit:
java.util.ConcurrentModificationException: too much contention on these
datastore entities. please try again.
at
com.google.appengine.api.datastore.DatastoreApiHelper.translateError(DatastoreApiHelper.java:39)
at
com.google.appengine.api.datastore.DatastoreApiHelper$1.convertException(DatastoreApiHelper.java:76)
at
com.google.appengine.api.utils.FutureWrapper.get(FutureWrapper.java:106)
at
com.google.appengine.api.utils.FutureWrapper.get(FutureWrapper.java:90)
at
com.google.appengine.api.utils.FutureWrapper.get(FutureWrapper.java:90)
at
com.googlecode.objectify.cache.TriggerFuture.get(TriggerFuture.java:99)
at
com.googlecode.objectify.util.FutureHelper.quietGet(FutureHelper.java:26)
at
com.googlecode.objectify.cache.TransactionWrapper.commit(TransactionWrapper.java:44)
I would really like to know if this is a bug (I really hope so) or a
limitiation of the Task Queue service.
On Tuesday, May 8, 2012 5:51:08 AM UTC-4, FastGeert wrote:
> Hi,
>
> last night our application suffered
> from java.util.ConcurrentModificationException on committing a transaction
> with only task queue entries.
>
> The transaction only had to persist 5 task queue entries, no additional
> changes needed to be committed in the transaction.
>
> After plunging through the documentation I conclude that this must be a
> bug in App Engine.
>
> Any thoughts on this ?
>
--
You received this message because you are subscribed to the Google Groups
"Google App Engine" group.
To view this discussion on the web visit
https://groups.google.com/d/msg/google-appengine/-/nMlDU-KyL5MJ.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/google-appengine?hl=en.
